Chimney cap



Jan. 6, 1942. E. VZIMMERMAN 2,269,050

CHIMNEY CAP Filed Nov. 1, 1939 Zmventor Emil Zjmmbrm 012 3g I aw, 4'.0g,

(Ittorneg Patented Jan. 6, 1942 UNITED STATES PATENT J OFFICE;-

p fcnnvnvavcn Emil zinimerman, Everett, Wa'sln U Application November 1,1939, Serial no. 302,354. 7 j I 10 Claims,

My invention relates to a chimney cap, that is, a device intended forapplication to-the'upper end of a chimney or other flue pipe, for-,thedual purpose of preventing down drafts, which sometimes occur. fromadverse wind oratmospheric conditions, and of employin the availablewind, Whether strong or light, and from whateverdidicated, which socontrols the movement of .the

rection, to assist in creating an upward draft, n

gree, assist in withdrawing the-'smoke-and gas from *the' flue. Suchrotatable ,caps,however,- have certain definite and well knownobjections, not the least of which is that being exposed to the weatherand being generally of inexpensive sheet metal construction, theyshortly begin to rust and stick, and then are worse than'no'cap,

Devices for such purposes as heretofore known have also taken the formofconcentric conical and frusto-conical structures in variouscombinations, surmounting the chimney; the surrounding' sleeves beingopen to the wind, the whole arranged with the intent that the windentering at the lower end of such sleeves will pass out at the upper endand will tend to create something of an upward eductor effect, tendingto withdraw the smoke and gas from the flue round about a centralinverted conical deflector, but such devices have been found lacking inpractical application' in that the 'windwill not follow the in-. tendedpath, but will tend to sweep generally horizontally around the conicaldeflector, wherefore its eductor effect is minimized, and whereby the:wind itself maytend, by eddy currents, to

interfere with the up draft, rather than t assist in creating the up drg l provide a device for application as'an immovable cap to a chimney orother fluewhich, having no moving parts, is not subject to theobjections attaching to the rotary caps, and which is so It is theobject-of my invention; therefore, to

constructed as to avoid the drawbacks of the type windthat the windiscaused to move through the. device in such away that it ishardlypossible to create eddy currents or down drafts into the lime, and insuch a way that the wind cannot sweep through the capin any'mannerexcept such as will induce an upward draft through the flue; in otherwords, it is an object to produce a device for. sucha' purpose, whichis. so constructed as to prevent, positively, mere sweeping through 'ofthe wind around andabout deflectors ina manner notintended, and notproductive of the desired final up draft within the flue.

, It is a further objecttoprovide such a cap which while not rotary, iopen in all directions,-

so that it will operate fromwhatever quarter the wind'pmay come, yetwill function asin'tended, re,- gardless of thewinds direction; whichispositively ,closed against direct down drafts or through drafts of anysort; in which the internal partsjare protected and not likely tovcollect rain water; in which the air currentsand the smoke currents areguided and afforded ample passage areas; andhwhich, may besimply andruggedly constructed, of sheet metal, and which may therefore beinexpensively constructed.

With .these and other objects in mind, as will appear as thespecification progresses, my inventioncomprisesthe novel chimney cap andthe novel, construction and arrangement ,of the several parts thereof,as shown in the accompanym drawing in a preferred form, and as will bemorefully, disclosed in thisspecification and definedby the claims.

Figure 1 isa top plan Viewwith'parts broken Figure 3 is an isometricview, with parts broken away to illustrate the interior construction.The'device is formed as an upstandinglcollar l, vvhich ispreferably ofsquare or rectangular form incross section, to fit upon and extendupwardly from the chimney 9. At its base it may be variouslyformed to,fitupon the. chimney,,as

for instance by providing it with the sleeve Ill. The particularformation of the collar in, this re spect islimmaterial. It only to benoted that it is carried by and extends upwardly from the chimney 9,substantially in line with the chimney flue 9|, and that the collar,being ofv sheet metal, anclof aboutthe cross-sectional area of theexterior of thechimney, has an internal cross-secti-onalareaconsiderablyin excess of the area At its top the collar I is closed by aplate or top I2, which is preferably relatively flat, so that it createsno appreciable change of direction of the wind flowing over it, and justbelow the top it is provided with openings I I in each of its foursides, for entrance of wind and for exit of wind and smoke. Theseopenings lie in the upper half of the collar, and the total area of eachis approximately equal to the cross-sectional area of the flue 9|.Instead of one continuous aperture II, several individual apertures maybe provided, if preferred. It appears more desirable, however, to employone individual aperture in each face or wall of the collar, rather thansever-- al smaller apertures in each wall.

In its interior the collar I is divided by twov partitions 2, whichextend diagonally from, corner to corner, and therefore cross in thecenter of the collar, their junction forming a vertical centrallydisposed line 2I.. These partitions 2 extend, unbroken and imperforate,from the top plate I2 downwardly to a level at below the lower edge of.the apertures I I. They divide the upper portion of the interior of thecollar into four sectors, and each of these sectors has, in the sidewall of the collar, one of the apertures II, but only one. suchaperture; A hollow, inverted, pyramidal deflector 3., formed of sheetmetal or the like, is centrally disposed within the collar, the marginaledges of its. base being spaced from the adjacent walls of th collarpreferably, to provide smoke outlets of ample cross-sectional area ascompared to the flues cross section, and these marginal edges 30 arelocated above the lower edges 20 of the partitions 2, but preferablybelow the lower edges of the apertures II so that the sides of thepyramid are inclined upwardly and outwardly in alignment with thecorresponding apertures, the drawing showing such deflector sidesdirected toward substantially the center of such openings. Th margins30, therefore, lie. between the lower edges 20 of the partitions and thelower edges of the apertures II. The interior of this pyramidaldeflector 3 admits to each one of the sectors de-' fined by the crosspartitions 2, yet its margin 30 is above the bottom 20 of each sector.The term pyramidal is used generically to embrace pyramids having anynumber of. sides, unless otherwise specified, so that it would include aconical shape,.since a cone is merely a special type of pyramid, namely,a regular pyramid having. an infiinite number of triangular lateralsurfaces.

Preferably a four sided pyramid is used, as shown,

with each edge 30 disposed parallel to a side of the square orrectangular collar I.

As a refinement, preferably employed, curved baffles 4 may be providedin each sector, curving inwardly and downwardly from the upper edge ofeach aperture I I towards the. junction of the line 2| with the loweredges 2a of the partitions, or towards the apex of the deflector 3.Though it. is considered undesirable to permit the partitions 4 Thesebaflles 5 serve to entrap and direct inwardly air which might otherwisepass over the top of the cap, and they serve much as do awnings to deteror prevent the entrance of rain water.

Smok rising from the flue 9| will tend, if not acted upon by aircurrents or down drafts, to divide at the deflector 3 and to pass out onall sides thereof and into each one of the sectors, and thence outthrough the apertures II. However, if the air is moving, whether thewind be light or strong, it tends to enter as indicated by the arrow Ain Figure 2, and for the moment we may assume that the air direction isperpendicular to the face of the collar which contains the aperture atthe left of Figure 2. The air entering at A isv deflected downwardly andcaused to converge into the angl of the partitions 2 by unbrokenpartitions and the curved interior baffle 4. However, it moves inwardsufliciently that it passes inside the margin 30 of the deflector 3, andhas no appreciable tendency to pass downward between this margin 30 andthe left-hand wallof the collar. Entering the deflector 3, it can onlyescape by reversing its direction and moving upwardly, as indicated bythe arrow B, and then in the opposite sector, at the right, it tends topass out through the upper portion of the aperture II, as indicated bythe arrow C, being aided in its change of direction by the wall of thedeflector 3 and by the curved interior baflle 4 inthe right-hand sector.Thus its direction is necessarily upward and outward, and it therebyentrains the smoke from the flue 9|, which now tends to rise into theright-hand sector, as indicated by the arrow D, and this smoke, directedoutwardly by the side of the deflector, passes out of the lower portionof the aperture II as indicated by the arrow E, aided by the aspiratingeffect of the air also passing through the aperture. The cross-sectionalareas of the restricted portions of these passages are sufficient toafford the movement of air or smoke as indicated, without appreciablerestriction of flow nor tendency to eddy.

While opposite sides of the collar preferably are disposed paralleltothe prevailing wind, the direction of the wind is not alwaysperpendicular to any given face or wall of the collar I, but at timeswill be at an angle thereto. Let us assume to extend. below the level ofthe edge 2-0,, yet, it is that it is at and thus equally strikes twoadjoining perpendicular walls of the collar. It tends to enter theaperture II in each of these walls, but can not pass immediately throughand out the apertures in the opposite walls, because it is interceptedand blocked by the imperforate diagonal partition 2, and is directeddownwardly by the curved interior baflies 4, and is caused to convergeto the junction 2| of the partitions 2, wherefore it is caused to enterthe conical deflector 3, and to pass downwardly thereinto, and thenupwardly again, but at the opposite side of the partition firstencountered. Passing upward only at the, opposite side of; thispartition, this wind can only pass out of the apertures I I- at theopposite side of such; p rtition. Thus it follows, fromthe use of thecross partitions 2, that the air musta-lways. wholly or certainly in. am jor part, pass into, the, conical deflector 3, before it can passupwardly, that it can only pass upwardly because it is so, directed andbecause the only escape is, above, and when it passes upward- 15 it, canonly pass outwardly at the opposite side of thepartition or partitionswhich barred its through passage; from all this it follows that thewind, in escaping, must entrain smoke from the flue 9|. Down drafts arethus prohibited, and the wind, whether light or heavy, willautomatically and of necessity entrain upward movement of the smoke. I c

What I claim as my invention is:

1. A chimney cap comprising a collar formed as an upward extension ofthe chimney, and closed at its top, having openings in all its sidesadjacent its top, upright partitions extending across the interior ofthe collar, subdividing it into at least four sectors, the partitionsextending from the closed top downwardly to a level below said openings,and being imperforate throughout such extent, whereby communicationbetween sectors can be had only beneath the partitions, and a hollow,inverted pyramidal deflector disposed with its apex spaced beneath thejuncture of the partitions, the edges of said pyramidal deflector beingdisposed above the level of the lower edge of the partitions, andinwardly from the walls of the collar, to leave an annular smokepassage, and such edges being further disposed outwardly of the junctureof the partitions, to direct air which enters at one opening downwardlyat the corresponding side of the partitions and then upwardly at theother side thereof, for discharge with entrained smoke, through anopening at such other side. I

2. A chimney cap comprising a collar formed as an upward extension ofthe chimney, and closed at its top but laterally open on all sidesadjacent its top, imperforate partitions fixed within the collar,extending from its closed top downward completely through and to a levelbelow its laterally open portion, and intersecting at about the centerline of the collar to divide the same lengthwise into at least foursubstantially equal sectors, and a hollow, inverted pyramidal deflectordisposed with its apex spaced beneath the junction of the lower edges ofthe partitions, and with its basal edges extending between adjacentpartitions, and spaced from the adjoining collar wall to afford a smokepassage from the flue beneath, in each sector.

3. A chimney cap comprising a collar formed as an upward extension ofthe chimney, and closed at its top but laterally open on all sidesadjacent its top, imperforate partitions fixed within the collar,extending completely through its laterally open portion and downwardbelow such portion, and dividing the collar lengthwise into at leastfour sectors, a hollow inverted pyramidal deflector disposed with'itsapex spaced beneath the partitions, and with its basal margin above thelower edges of the partitions, and spaced inside the walls of thecollar, to afford a smoke passage from the flue beneath into eachsector, and a bafile in each. sector curving from a point adjacent theupper edge of each opening inwardly towards the partitions forming suchsector and downwardly at least to a location substantially even with thelower edge of the collar opening.

4. A chimney cap comprising a collar closed at its top, and formed as anupward extension of the chimney, and laterally open on all sidesadjacent its top, two imperforate vertical partitions fixed inintersecting relationship within the collar, extending from its closedtop downwardly through its laterally open portion and to a level belowthe lower edge of the collar opening, dividing the collar lengthwiseinto four sectors, and a hollow inverted pyramidal deflector disposedwith its apex spaced beneath the intersecting line of the partitionsandwith its sides lying in planes which are directed upwardly and out-"wardly to intersect the collar in a line substantially above the loweredge of the corresponding collar opening, the defiectors sides stoppingshort of the collar to dispose the deflectors upper edges above thelower edges of the partitions but below the lower edges of the openings,and spaced inside the walls of the collar, to afford a smoke passagefrom the flue beneath said deflector through each sector directedoutwardly toward the collar opening.

5. A chimney cap comprising a collar which is rectangular in crosssection, formed as an upward extension of the chimney flue, said collarbeing closed at its top but laterally open at the top of each wall ofthe collar, two imperforate, diagonal, vertical, fixed partitionsextending from its top closure downwardly and from corner to cornerwithin the collar, crossing at its center, and dividing the collarlengthwise into four sectors, and an inverted, hollow, rectangularpyramidal deflector disposed with its apex spaced below the junction ofthe partitions, and with its basal edges above the lower edge of thepartitions, each base edge of the deflector bridging between theadjacent partition portions and disposed parallel to and spaced from thecollar wall in a sector to afiord a smoke passage from the fluebeneathinto each sector.

6. A chimney cap comprising a collar which is rectangular in crosssection, formed as an upward extension of the chimney flue, said collarbeing closed at its top but laterally open at the top of each wall ofthe collar, two imperforate, diagonal, vertical, fixed partitionsextending from its top closure downwardly and from corner to cornerwithin the collar, crossing at its center, and dividing the collarlengthwise into four sectors, an inverted, hollow, rectangular pyramidaldeflector disposed with its apex spaced below the junction of thepartitions, and with its basal edges above the lower edge of thepartitions, each base edge of the deflector bridging between theadjacent partition portions and disposed parallel to and spaced from thecollar wall in a sector, to afford a smoke passage from the flue beneathinto each sector, and a baflie in each sector curving from the upperedge of each collar opening inwardly into the angle between thepartition portions forming such sector and downwardly at least to alocation substantially even with the lower edge of the collar opening.

7. A chimney cap comprising a collar which is rectangular in crosssection, formed as an upward extension of the chimney flue, said collarbeing closed at its top but laterally open at the top of each wall ofthe collar, two imperforate, diagonal, vertical, fixed partitionsextending from its top closure downwardly and from corner, to cornerwithin the collar, crossing at its center, and dividing the collarlengthwise into four sectors, an inverted, hollow, rectangular pyramidaldeflector disposedwith its apex spaced below the junction of thepartitions, and with its basal edges above the lower edge of thepartitions, each base edge of the deflector bridging between theadjacent partition portions and disposed parallel to and spaced from thecollar wall in a sector to afford a smoke passage from the flue beneathinto each sector, and a baffie for the collar opening including aportion in each sector curving from the upper edge of each collaropening inwardly into the angle between the partition portions formingsuch sector and downwardly at least to a location substantially evenwith the lower edge of the collar opening, and also a portion extendingfrom the collar upwardly and outwardly in continuation of said firstbaffle portion.

8. A chimney cap comprising a collar formed as an upward extension ofthe chimney, and closed at its top, having openings in all its sidesadjacent its top, upright partitions extending across the interior ofthe collar subdividing it into at least four sectors, the partitionsextending from the closed top downwardly to a level below said openings,and being imperforate throughout such extent, whereby communicationbetween sectors can be had only beneath the partitions, and a hollow,inverted pyramidal deflector disposed with its apex spaced beneath thejuncture of the partitions, the edges of said pyramidal deflector beingdisposed above the level of the lower edge of the partitions, andinwardly from the walls of the collar, to leave an annular smokepassage, and such edges being further disposed outwardly of the junctureof the partitions, to direct air which enters at one opening downwardlyat the corresponding side of the partitions and then upwardly at theother side thereof, for discharge, with entrained smoke, through anopening at such other side, and a baflie in each sector curved, from alevel with the upper edge of the corresponding opening, inwardly anddownwardly, and disposed generally transverse to air entering at suchopening, to direct air entering by such opening inwardly and downwardlytowards the apex of said inverted pyramidal deflector, or to direct airrising from such deflector outwardly through such opening.

9. A chinmey cap comprising a collar formed as an upward extension ofthe chimney, closed at its top, and having openings on all sidesadjacent its top, relatively crossed upright partitions extendingdiametrically from side to side across the interior of the collar, andfrom its top closure downwardly to a level below the collars openings,and being imperforate throughout such extent, said crossed partitionsdividing the interior of the upper portion of the collar into sectors,between which communication can only be had beneath the lower edges ofsaid partitions, and a hollow, inverted pyramidal deflector disposedwith its apex spaced beneath the juncture of the partitions, and withits sides directed upwardly and outwardly towards the openings, butterminating in edges which are spaced above the lower edges of thepartitions but not above the lower edges of the collars openings, andintermediate the side walls of the collar and the juncture of thepartitions, thus to define smoke passages from the flue between thedeflectors edges and the collars side walls, and to define a separatepassage, first directed downwardly and then upwardly, for air whichenters at an opening at one side of the collar, and directing itoutwardly through the opening at the other side thereof.

10. A chimney cap comprising a collar formed as an upward extension ofthe chimney, and closed at its top but laterally open on all sidesadjacent its top, imperforate partitions fixed within the collar anddividing it into at least four sectors, a hollow, inverted pyramidaldeflector disposed with its apex spaced beneath the partitions, and withits sides directed upwardly and outwardly towards the correspondingcollar opening, but stopping short thereof to dispose its upper edges inspaced relation to the walls of the collar, to afford a smoke passagefrom the flue beneath said deflectors through each sector di-- rectedoutwardly toward the collar opening, and means between said partitionsand the collar, disposed opposite each opening, operable to deflect airflowing in through any opening downward alongside a partition into saidhollow inverted deflector.

EMIL ZIMMERMAN.

